I have (almost) no bass!

[NJProjectionist]

Hi all,
Very new to REW, but have been doing the Home Theater thing for about 20 years, and before that, a 22 year career as a motion picture projectionist and sound technician. So I do have a grasp of the fundamentals. But with that said, I think something is set horribly wrong in my Denon X-3300W AVR. I have never really had punchy bass. It's been there and sounded "meh-to-OK" but I never did any form of measurements int he past beyond SPL checks (85dB-C/Slow). This weekend I used my DaytonAudio EMM-6 calibrated mic (with cal file loaded) and took a few measurements and was utterly dismayed at what I'm seeing. I will attach the measurements file, but here's a screenshot of what REW captured. Settings follow the screen grab.

I have the left main disconnected, and the sweep (20-250) was performed through just the subwoofer(s). The orange trace is the Polk Audio, the green trace is the SVS, and the blue trace is with both running. The bass management on the X-3300W is set to LFE (only) and the LPE LPF was set to various values with no appreciable change here. All speakers are set to small, and for the purposes of these tests all crossovers were set to 110Hz. The LPF dial on both subs was turned all the way up full. At the time, I had no Audyssey room corrections done; everything was manual. I had never done an Audyssey setting, in fact. All equalization was off, dynamic EQ and volume were off, speech and bass bosting were off. My PC is connected to the AVR via a front-panel HDMI connection, and I can control the settings of the AVR with the computer, as well as run REW. If you need screenshots of my setup parameters I can upload those too.

Now these aren't high-end subs by any means, but to have virtually nothing below about 70 or 80 Hz is ridiculous. The room is untreated, with parallel plaster walls, so it will be very live. I'm not going to get perfection, but I would like to get things at least sort-of-not-horrible for now, if that's possible! I was expecting wild room modes and standing waves, but I wasn't expecting this.

I am extraordinarily new to this software -- I've done accoustic checks with a Gold Line RTA for Dolby Stereo cinema processor room EQs in the 80s and 90s, but this is a whole new game for me! I've watched a dozen videos and followed the setup processes as best as I could understand but obviously I've missed something crucial. So I would respectfully ask that any kind soul here offering assistance, please know that I won't really understand any deep concepts and esoteric settings. I'm just trying to get a better baseline at this point, and I will need some hand-holding (sorry for that in advance).

 

[John Mulcahy]

Beware of Windows being helpful. Nowadays mics with stereo outputs are assumed by Win10 to be noise cancelling and are processed accordingly. A measurement mic has the same signal on both channels so the effect is to roll off the low end. It can be fixed by selecting Disable all enhancements on the Advanced tab of the Windows audio properties for the mic input.

 

[NJProjectionist]

Audio enhancements were off, and there was no level boost. This has me completely stumped. Is there anything in the AVR that would prevent low frequencies from being sent to the subs, beyond the settings I've already referenced? It's very odd because I'm in the room when the sweeps are done, and it doesn't sound (to my ears) like the low end rolls off. I'm leaning more towards a software or mic issue, but the mic is brand new.

 

[John Mulcahy]

You haven't made any input or output device selections in REW so (1) you will be using the Windows default devices, which can change and (2) you won't be able to access the individual channels of the HDMI connection, the signals will go to L and/or R. Depending on AVR mode setting that may or may not redirect to the sub. Best option on Windows is generally to use an ASIO wrapper like FlexASIO or ASIO4All and choose the ASIO driver setting in REW, that way the individual channels of an HDMI multichannel PCM connection can be accessed. Note, however, that some AVRs don't provide multichannel support on front panel inputs. Jerry's guide is good for getting setup with an HDMI connection, it is aimed at USB mics but there isn't really any difference when using an analog mic.

 

[NJProjectionist]

I did try ASIO4All but could not get it to work, so I figured as a baseline I would just stick to the Java setting, since just about every REW video I've seen shows it that way, at least to start. Eventually this will be something I'll need to do, but for now, understanding why my bass rolls off to nothing so high is priority number one. The calibrated mic in question is a USB mic connected to my Windows PC, and the output goes from a USB-C port to the AVR.

Here are my first two settings screens

 

[John Mulcahy]

You mentioned an EMM-6 in your initial post, did you mean UMM-6? If so, make sure the Disable all enhancements box is ticked on the Windows enhancements tab, it isn't sufficient to just not select any enhancements.

It is safer to select the actual device rather than use the default, if some other audio interface gets connected or disconnected that can change the default device. That also means REW will know you are using a USB mic and can treat it accordingly, taking into account the input volume and mic cal file sensitivity figure to show correct SPL figures.

 

[NJProjectionist]

I erred when I said it was an EMM-6; it is in fact an UMM-6, and I have a cal file for my specific S/N. On this system I cannot find any option to disable enhancements. Where specifically do I find it?

Meanwhile, I re-connected everything briefly and this is the setup screen with both the mic and the AVR attached.

 

[John Mulcahy]

Just noticed the input device buffer setting, bring that back to 32k.

Here is an example of the Enhancements tab on the properties for an input. There isn't always an enhancements tab present though so if you don't have one you should be OK.

 

[NJProjectionist]

There is no "Enhancements" tab for the UMM-6.

 

[madski]

I'm having basically the same issue. I do have enhancements turned off for the AV Pre in Windows but still very little low end? Light green and orange are SVS SB13 Ultras and the dark green is a PE Dynomax 18" sealed box. My plot looks pretty similar to the OP. Running through an Anthem AVM60 preamp.

 

[NJProjectionist]

How does it sound? Mine sounds better than it looks. I'm thinking I've got software issues first and foremost.

 

[madski]

I'm just trying to get it sorted with the Dynomax being added to the system. I might run ARC and see what it plots for the subs. Just to rule out that end of things. I haven't really spent any time listening/watching anything yet. This has been bugging for a week. Hope some of the folks here can help.

 

[John Mulcahy]

Some computers have other interfaces for audio behaviour. As an example, ASUS laptops have an "AI Noise cancelling microphone" feature that needs to be turned off in the myASUS application. Beyond that bass management may be coming into play without redirection - those roll-offs look to be about 24 dB/octave from about 80 Hz which would be typical of a bass management filter.

 

[UKSPAWN]

i would agree with John, there is some software somewhere doing something to the output. (or input)

Make sure your output/'speaker' are configured as FULL RANGE for a start. - in the sound settings click the "configure" button and assign the appropriate channels to full range

Settings > Sound > Sound contol panel - select output device, click "configure" , NEXT then check the box for full range.

(if ytou cant find it...

1. Press Win + R to open the Run Command dialog box.
2. Type control mmsys.cpl sounds and press Enter.

)

 

[madski]

Eureka! At least in my case it was a matter of making sure to disable "enhancements" for BOTH the speakers and the mic in device manager. Below is a raw plot (nothing applied to it) but response down low is finally there:

 

[UKSPAWN]

good stuff